#include<iostream>
using namespace std;
int fib(int n)
{
  if(n == 0)
  {
    return 0;
  }
  if(n <= 2)
  {
    return 1;
  }
  return fib(n-1) + fib(n-2);
}
int main()
{
  int n = 45;
  int result = fib(n);
  cout << result << endl;

  return 0;
}
